We report the case of a 70 years old man admitted to our coronary care unit because of atrial fibrillation, non-ST-elevation myocardial infarction and cardiogenic shock. Emergency coronary angiography showed a 99 % stenosis of the circumflex coronary that was successfully treated with a bare metal stent. Atrial fibrillation was cardioverted to sinus rhythm. Nevertheless, no hemodynamic benefit was observed. Transesophageal echocardiography (TEE) showed rupture of the papillary muscle (PM). The patient underwent emergent mitral valve replacement. Surgical visualization of the mitral valve confirmed the rupture of the antero-lateral PM. The postoperative course was uneventful and the patient recovered fully. This case highlights that even small myocardial infarction may have dramatic clinical presentations such as PM rupture with cardiogenic shock. Clinical suspicion and rapid confirmation of the diagnosis by TEE are essential requirements for successful treatment.